Railway signal



(No Model.) 2 Sheets-Sheet 1. Q

G. W. PBIDHAM.

RAILWAY SIGNAL.

Patented Nov. 16, 1886.

( MfldeL) 2 Sheets Sheet 2.

C. W. PRIDHAM.

RAILWAY SIGNAL.

Patented Nov. 16, 1886.

N. FETERi PMlo-Lilhourapllu. Washingion. v.0

UNITED STATES PAT NT EEicE.

CHARLES WILLIAMPRIDHAM, OF EARLS COURT ROAD, COUNTY OF MIDDLESEX, ENGLAND.

-RAlLWAY-SlGNAL.

SPECIFICATION forming part of Letters Patent No. 352,571, dated November 16, 1886. Application filed October 21, 1885. Serial No. 160,557. (No model.) 7

To all whom it may concern.- 7

Be it known that I, CHARLES WILLIAM PRIDHAZM, a subject of the Queen of Great Britain, residing at 62 Hogarth Road, Earls Court Road, in the county of Middlesex, England, physician, have invented certain new and useful Improvements in Train-Signaling on Railways, of which the following is aspecification. The object of my invention is to enable an operator at a station or in a signal-cabin to transmit electric telegraphic signals to the driver of a train, especially such signals as are required to instruct the driver whether to stop or to proceed. These signals are received upon an instrument provided on the train, and preferably on the engine within sight of the engine-driver. Among the advantages derived are that the signals cannot be obscured by fog. and can be transmitted without difficulty for longer distances than by the semaphore apparatus in common use. The instrument upon the train is provided with asignal arm or indicator, which is connected with the armature of an electro-magnet in such manher that when an electric current passesin the coils of the magnet and the armature is at tracted the signal arm or indicator is brought toaposition whichindicates safety or go on. The current to produce this effect is transmitted from a signal cabin or station by means of an ordinary circuit-closingkey, with which the signal-man is provided. The current passes from a battery, through the key and a line-wire, to a contact-post by the side of the line of railway. The train carries a metal bar, which rubs over the insulated head of the contact-post, and the current passes from the head of the post to the ploy is simply a repetition of the apparatus already described, and comprises another linewire, a key, another contact post or posts on contact-bar, thence to the electro-magnet the line, and another electro-magnet in theinstrument on the train. The only material difference is that the armature of the latter electro-magnet is differently connected with the signal arm or indicator, and when attracted places it at the danger or stop position; but in place of this arrangement, by which the signal arm or indicator is set by electrical means to the danger or stop position, it maybe so set by means of parts moved mechanically when a bar or instrument on the train strikes against a post by the side of the line. a

In the drawings, Figure l is a front view, and Fig. 2 is a back view, of the instrument on the train. Fig. 3 is a diagram of the circuit arrangements. Fig. 4 is an elevation of a contact-bar on the train and a contact-post on the line. Figs. 5 and 6 show a modification, and are sectional elevations of mechanism for setting the signal arm or indicator to the danger or stop position withoutthe aid of an electric current. These parts are also indicated in Fig. 4.

In Fig. 3 the inclosure (marked A) represents the signal cabin or station. 13 represents one of the rails of the railway; O, a vehicle running thereon; D, a battery; E and F, two finger keys; G, an insulated line-wire; H, a contact-post by the side of the line; I, a contact-bar carried by the train. strument containing the electro-magnet, the armature of which when attracted puts the signal-arm to the go on or safety position. L are the wheels of the train. lViththe parts in the positions indicated in the figures, the circuit is closed, and it can be readily traced from D by E, G, H, I, K, L, and B back to-D, the battery D and the rails 13 both being connected to earth. The signal arm or indicator on the vehicle consequently assumes the safety or go-on position. is in connection, in a precisely similar manner,

with another linewire and another contact post or posts on the line which come in contact with another contact-bar on the train connected with another electro-magnet, whence the circuit is completed by the wheels L and rails B, as before. The sole difference is that the armature of the second electro-magnet is K is the in-.

The other key, F,

arm or indicator N. It is shown in the figure in the danger or stop position, anditis retained there by a pin, on a lever, O, which is now engaged in a notch in a half-wheel, M,

. fixed on the axis M. The lever O carries an iron armature, 0, immediately over the poles of the electro-magnet P. This magnet is in the circuit D E G H I KL B. When the circuit is closed, the magnet attracts its armature, the pin 0 is lifted, and the signal arm or indicator falls by its own weight to the safety or go on position. Q is another electro-magnet. Its coils are in the duplicate circuit, or that through the second line-wi re. Thiscircuit is entirely separate from the first, except that the same batterymay serve,and the return in both cases is by the wheels and rails and the earth connection which the rails form.

There are separate contact-posts and contactbars, and preferably these are at a distance from the first toward the other side of the line. When the key F is closed and the corresponding contact-bar is against its contact-post, the magnet Q attracts its armature R. The armature R has it fulcrum at R, and it carries an arm, R, which acts against the under side of the half-wheel M. When the armature R is attracted, the half-wheel M is partly rotated, the signal arm or indicator, is raised, and the pin 0 drops in and retains it until the lever O is again lifted by the magnet P to give the safety or go on signal. In this arrangement the danger or stop signal is given only when the key F is closed, and the safety signal onlywhen the key E is closed; or a single double-acting key may be employed.-

Various sorts of contact-makers may be employed; but that which I prefer consists of a light T- iron barsay about twelve feet long.

It is hung horizontally beneath the tender of line of railway-one toward the right side of 4 one of the carriages of the train, about a foot within the line of one of the rails and the same distance from the road. The fiat of the T is on the under side, and the ends of the bar are curved upward, so as to rise three or four inches above the middle'of the bar.

The bar may be hung underneath the car riage by leather straps, or in any other convenient way which insures suflicient insulation'and allows the bar to swing freely. The contact-makers on the. train work in connection with posts arranged in 'pairs along the the line, the other to the left. The heads of these posts are globular and of cast-iron. They stand to a height about an inch to an inch and a half above the under surface of the T-iron bar, so that the head of the post with certainty comes into contact wit-h the under side of the bar and establishes good electrical contact as the train passes. The globular head of each post is insulated, and is electrically connected with the line-wire. In the modification illus; trated by Figs. 5 and 6 the key F and the linewire connected with it are dispensed with, while the corresponding contact-posts and contact-bar on the train are retained, but they have no electrical connections. The electromagnet Q also is dispensed with, but the arm R", with its fulcrum R, is retained. A link, 8, connects it with a flexible diaphragm, T, which closes acuplike vessel, U, from which a pipe, V, passes to the interior of the indiarubber ball W. v The ball W is held between two concave surfaces, of which one is movable, being mounted on a lever, X, having its fulcrum at X. Along coiled spring of wire, Y,

connects the lever .X with the contact-bar Z.

again in the manner already described, if the danger or stop signal is not required.

What I claim is- 1. The combination of apparatus for trainsignaling, consisting of the following parts: at the signal-cabin a battery and finger-keys for applying the battery to one or other of two line-wires, on the line the said insulated linewires and contactposts connected therewith, and on the train a semaphore-arm or like signal apparatus; also two contact-barsmaking contact with the contact-posts, and means for raising the signal to allow it to be latched in the danger position, and independent apparatus for lifting the latch when the signal is not required to be retained.

2. The combination of apparatus for trainsignaling, consisting of the following parts: at the signal-cabin a battery and afinger-key for applying the battery to a line-wire; 'on the line the said insulated line-wire and a contact post or posts connected therewith, and on the train a semaphore-arm or like signal and-me.- chanical apparatus for raising the signal as the train passes a contact-post; also a contact-bar making contact with the contact-posts, and an electro-magnet or equivalent instrument for lifting the latch when the signal is not required to be retained.

CHARLES WILLIAM PRIDHAM. 

